The invention concerns presentation of a current version of a document retrieved from a data repository. The presentation indicates changes made in the document since the viewer accessed a previous version.
Information which is stored in computerized systems can change frequently, and without notice. As an example, software under development frequently involves many persons, and is commonly stored at a central location. Each person can change the software on an ad hoc basis, without knowledge of others.
In such systems containing changeable data, a person who examines information on a given day does not, in general, know whether, and how, the information has changed since a previous examination. Consequently, the person must spend time comparing currently available information with previous versions of the information.
Software exists for facilitating this comparison. For example, systems known as xe2x80x9cversion control systems,xe2x80x9d or xe2x80x9crevision control systems,xe2x80x9d store data which represents multiple versions of different documents, as indicated in FIG. 1A. In that Figure, the DATA is indicated, together with dashed loops which indicate the VERSIONs.
The loops indicate that the VERSIONs are contained in, and derivable from, the DATA. For example, each VERSION can be stored in its entirety. Alternately, a single VERSION can be stored in its entirety, and other VERSIONs can be stored in the form of differences between them and the single, entire VERSION.
The version control system reconstructs any selected VERSION for the user.
However, many such software systems suffer disadvantages. In general, some systems notify users of the occurrences of changes, but do not identify the changes themselves. Conversely, other systems identify the changes (generically, these systems are known as xe2x80x9cdiffxe2x80x9d systems), but only in response to identification of a particular pair of documents.
One form of the invention observes a user""s examination of a document contained in a repository. The invention then continually monitors that document for modifications. When the user examines the document at a later time, the invention presents the document in the current, later, form, and indicates the modifications occurring since the user last viewed the document.